With recent progress in the network technology, traffic carried in a network such as the Internet has kept increasing. The IP (Internet Protocol) used in the Internet and the like plays a role to transit a packet to the counterpart apparatus. The communication realized by the IP is “communication without reliability”. That is, the IP does not assure the arrival and the order of arrival of data.
The TCP (Transmission Control Protocol) is used to realize “communication with reliability”. Hereinafter, it is assumed that the “communication with reliability” refers to communication in which transmitted data is forwarded without excess or deficiency in the order of transmission.
While the TCP currently occupies a large part of traffic, the actual condition is that its performance is unstable and variable. In order to provide multi-media distribution services and the like of video, it is necessary to stabilize the TCP performance.
The TCP bandwidth control technique is one of known techniques related to the TCP performance. The TCP bandwidth control technique relates to controlling the traffic to a predetermined amount or less, which is a technique in which, basically, the congestion of the network is avoided by assigning priority according to the type of traffic and discarding traffic with a low degree of priority.